Wireless communication systems generally use multiple frequencies to provide greater bandwidth than would be possible using a single frequency. Such systems, particularly large-scale systems such as those used for telecommunications, are typically divided into cells that provide wireless coverage to a particular area, although some overlap may exist between cells. In some systems, cells may be further divided into sectors.
The use of multiple frequencies may cause interference between cells or between sectors. For example, random access transmissions in neighboring cells generally use the same frequency subbands. This may result in increased interference from the neighboring cells, thereby degrading random access performance. Moreover, the number of sequences used for random access planning in the neighboring cells is limited, which may result in two neighboring cells using the same sequence. This may increase the probability of false alarms where a response to a random access request is transmitted by an incorrect cell, which results in degraded system performance. Improved methods are needed to minimize inter-cell and/or intra-cell interference.